(1) Field of the Invention
The present invention relates to an apparatus and a method for automatically performing chemical, biochemical and biological analyses.
(2) Description of Related Art
Automated analyzers are well known in the prior art and are used for example by diagnostic laboratories for the rapid and reliable detection of analytes in a variety of biological samples. Analyzers are routinely used to perform a wide variety of assays, most of which involve immunoassays which exploit the high affinity and selectivity of an antibody for its antigen.
Analyzers with very high throughput capabilities are usually modular in form, with each separate module performing a single step of the assay. For example, modules commonly exist for fluid liquid handling, incubating, vortexing, transporting and reading and analyzing the assay result. These modules are then robotically interconnected to provide full automation.
Although microtitre plate liquid handling systems and single function microtitre plate systems such as washers, incubators, agitators and readers are well known in the prior art, only a few examples of compact fully automated microplate analyzers have been disclosed.
One example of such an integrated analyzer is described in WO 2006/094388 A1 This analyzer comprises fully integrated subsystems for liquid handling and optical reading and allows the transport of microtitre plates and the parallel detection of several analytes in one microtitre plate using different photometric characteristics. A plurality of discrete carrier trays is used for holding and transporting microtitre plates and other assay consumables.
EP 0 918 221 B1 discloses an apparatus for performing automatic tests on samples for ELISA (Enzyme-linked Immunosorbent Assay) tests, which is constituted by two functionally separate regions of which the first, which permits interactive access by the user, permits loading of the samples, controls, calibrations, diluents and equipment necessary for performing the sampling and the dilutions. The apparatus then performs the operations relating to the sampling and dilutions of the samples and transports the plate to the second region in which the rest of the operations are performed, the first region being left free for the loading of further series. The device is further characterized by a series of containers for the storage of the auxiliary liquids for the process and for the collection of washings and waste.
EP 1 293 781 B1 discloses an automatic analyzing apparatus for detecting object substances in specimens such as for immunity analyses utilizing the reaction between antigen and antibody and chemicobiological analyses. The automatic analyzing apparatus comprises a reaction portion for causing a specimen substance to act on a reagent commensurate therewith in a reaction vessel, a detecting portion for detecting signals derived from the reagent and a cleaning portion for removing the specimen substance or unreacted reagent or cleaning reaction liquid after the reaction is complete. These reaction, detection and cleaning portions are arranged on turntables.
EP 0 353 591 B1 discloses a semi-automated biological sample analyzer for performing enzyme immunoassays for human IgE class antibodies specific for a panel of preselected allergens in each of a plurality of biological samples. The analyzer comprises a carousel for positioning and holding a plurality of reaction cartridges. Each reaction cartridge includes a plurality of isolated test sites formed in a two-dimensional array in a solid phase binding layer contained within a reaction well which is adapted to contain a biological sample to be assayed.
The region for the input of samples and equipment necessary for performing sampling and dilutions can be subject to contamination and liquid spillover. One disadvantage of prior art analyzers is that there is often an electrically driven drawer for containing the samples and equipment necessary for performing the sampling and dilutions. An electrically driven drawer is easily decomposed by contaminations. Therefore there is a need to have means of inserting samples whose functionality is not affected by contaminations or liquid spillover.
Analyzers can also be subject to operational errors despite automatic operation and minimum human intervention. Since the samples and equipment necessary for sampling can be very costly, especially in the case of biochemical and or biological clinical tests, there is a need to recognize operational errors to avoid waste of costly substances. The mechanisms for recognizing operational errors must also be inexpensive and uncomplicated, in order to avoid increasing the complexity of the fully integrated and therefore already complex analyzer.
In order to achieve high flexibility, it is necessary to integrate as much functionality as possible in an analyzer. Hence, solutions for increasing functionality without increasing complexity, cost and/or sensitivity are required.